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The Hacker News - Cybersecurity News and Analysis: side-channel attack

NetCAT: New Attack Lets Hackers Remotely Steal Data From Intel CPUs

NetCAT: New Attack Lets Hackers Remotely Steal Data From Intel CPUs

September 11, 2019Swati Khandelwal
Unlike previous side-channel vulnerabilities disclosed in Intel CPUs, researchers have discovered a new flaw that can be exploited remotely over the network without requiring an attacker to have physical access or any malware installed on a targeted computer. Dubbed NetCAT , short for Network Cache ATtack, the new network-based side-channel vulnerability could allow a remote attacker to sniff out sensitive data, such as someone's SSH password, from Intel's CPU cache. Discovered by a team of security researchers from the Vrije University in Amsterdam, the vulnerability, tracked as CVE-2019-11184, resides in a performance optimization feature called Intel's DDIO—short for Data-Direct I/O—which by design grants network devices and other peripherals access to the CPU cache. The DDIO comes enabled by default on all Intel server-grade processors since 2012, including Intel Xeon E5, E7 and SP families. According to the researchers [ paper ], NetCAT attack works simila
OpenSSH Now Encrypts Secret Keys in Memory Against Side-Channel Attacks

OpenSSH Now Encrypts Secret Keys in Memory Against Side-Channel Attacks

June 22, 2019Mohit Kumar
In recent years, several groups of cybersecurity researchers have disclosed dozens of memory side-channel vulnerabilities in modern processors and DRAM s, like Rowhammer , RAMBleed , Spectre, and Meltdown . Have you ever noticed they all had at least one thing in common? That's OpenSSH. As a proof-of-concept, many researchers demonstrated their side-channel attacks against OpenSSH application installed on a targeted computer, where an unprivileged attacker-owned process exploits memory read vulnerabilities to steal secret SSH private keys from the restricted memory regions of the system. That's possible because OpenSSH has an agent that keeps a copy of your SSH key in the memory so that you don't have to type your passphrase every time you want to connect to the same remote server. However, modern operating systems by default store sensitive data, including encryption keys and passwords, in the kernel memory which can not be accessed by user-level privileged p
NetSpectre — New Remote Spectre Attack Steals Data Over the Network

NetSpectre — New Remote Spectre Attack Steals Data Over the Network

July 27, 2018Mohit Kumar
A team of security researchers has discovered a new Spectre attack that can be launched over the network, unlike all other Spectre variants that require some form of local code execution on the target system. Dubbed " NetSpectre ," the new remote side-channel attack, which is related to Spectre variant 1, abuses speculative execution to perform bounds-check bypass and can be used to defeat address-space layout randomization on the remote system. If you're unaware, the original Spectre Variant 1 flaw (CVE-2017-5753), which was reported earlier this year along with another Spectre and Meltdown flaws , leverages speculative stores to create speculative buffer overflows in the CPU store cache. Speculative execution is a core component of modern processors design that speculatively executes instructions based on assumptions that are considered likely to be true. If the assumptions come out to be valid, the execution continues and is discarded if not. This issue could
OpenBSD Disables Intel Hyper-Threading to Prevent Spectre-Class Attacks

OpenBSD Disables Intel Hyper-Threading to Prevent Spectre-Class Attacks

June 20, 2018Swati Khandelwal
Security-oriented BSD operating system OpenBSD has decided to disable support for Intel's hyper-threading performance-boosting feature, citing security concerns over Spectre-style timing attacks . Introduced in 2002, Hyper-threading is Intel's implementation of Simultaneous Multi-Threading (SMT) that allows the operating system to use a virtual core for each physical core present in processors in order to improve performance. The Hyper-threading feature comes enabled on computers by default for performance boosting, but in a detailed post published Tuesday, OpenBSD maintainer Mark Kettenis said such processor implementations could lead to Spectre-style timing attacks. "SMT (Simultaneous multithreading) implementations typically share TLBs and L1 caches between threads," Kettenis wrote. "This can make cache timing attacks a lot easier, and we strongly suspect that this will make several Spectre-class bugs exploitable." In cryptography, side-channe
New 'Lazy FP State Restore' Vulnerability Found in All Modern Intel CPUs

New 'Lazy FP State Restore' Vulnerability Found in All Modern Intel CPUs

June 14, 2018Mohit Kumar
Hell Yeah! Another security vulnerability has been discovered in Intel chips that affects the processor's speculative execution technology—like Specter and Meltdown —and could potentially be exploited to access sensitive information, including encryption related data. Dubbed Lazy FP State Restore , the vulnerability (CVE-2018-3665) within Intel Core and Xeon processors has just been confirmed by Intel, and vendors are now rushing to roll out security updates in order to fix the flaw and keep their customers protected. The company has not yet released technical details about the vulnerability, but since the vulnerability resides in the CPU, the flaw affects all devices running Intel Core-based microprocessors regardless of the installed operating systems, except some modern versions of Windows and Linux distributions. As the name suggests, the flaw leverages a system performance optimization feature, called Lazy FP state restore, embedded in modern processors, which is resp
Linux TCP Flaw allows Hackers to Hijack Internet Traffic and Inject Malware Remotely

Linux TCP Flaw allows Hackers to Hijack Internet Traffic and Inject Malware Remotely

August 11, 2016Swati Khandelwal
If you are using the Internet, there are the possibilities that you are open to attack. The Transmission Control Protocol (TCP) implementation in all Linux systems deployed since 2012 ( version 3.6 and above of the Linux kernel ) poses a serious threat to Internet users, whether or not they use Linux directly. This issue is troubling because Linux is used widely across the Internet, from web servers to Android smartphones, tablets, and smart TVs. Researchers have uncovered a serious Internet flaw, which if exploited, could allow attackers to terminate or inject malware into unencrypted communication between any two vulnerable machines on the Internet. The vulnerability could also be used to forcefully terminate HTTPS encrypted connections and downgrade the privacy of secure connections, as well as also threatens anonymity of Tor users by routing them to certain malicious relays. The flaw actually resides in the design and implementation of the Request for Comments: 5961 ( RF
Stealing Encryption Keys Just by Touching a Laptop

Stealing Encryption Keys Just by Touching a Laptop

August 27, 2014Mohit Kumar
As far sci-fi movies have been entertaining the public, but their ideas have always been a matter of adoption in real life. Just like in any other sci-fi movie, simply touching a laptop can be enough to extract the cryptographic keys used to secure data stored on it. A team of computer security experts at Tel Aviv University (Israel) has come up with a new potentially much simpler method that lets you steal data from computers — Just Touch it — literally. WAYS TO ATTACK ENCRYPTION There are different ways of attacking encryption systems. On one side, there are security vulnerabilities and weakness in the encryption algorithms themselves that make it possible to figure out the cryptographic keys. On the other side, there are flaws and weaknesses in the people themselves that make it easier than it should be to force them to offer up the keys to decrypt something. But, Flaws and weaknesses in neither of which is necessarily quick or easy to find out, as there are seve
Cross-VM Side-channel attacks against cryptography keys

Cross-VM Side-channel attacks against cryptography keys

November 05, 2012Mohit Kumar
A group of researchers has developed a side-channel attack targeting virtual machines that could pose a threat to cloud computing environments. Side-channel attacks against cryptography keys have, until now, been limited to physical machines, this attack is the first such attack demonstrated on a symmetric multiprocessing system virtualized using a modern VMM (Xen). A side channel is a form of information leakage that arises as a byproduct of resource exposure, such as the sharing of memory caches. A side-channel attack exploits such leakage to steal secrets, such as cryptographic keys. " In this attack, the researchers were able to extract a private ElGamal decryption key from the target VM's libgcrypt library; the target was running Gnu Privacy Guard. Over the course of a few hours of observations, they were able to reconstruct a 457-bit exponent accompanying a 4096-bit modulus with high accuracy. So high that the attacker was then left to search fewer than 10,000 possible exp
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